The latest draft of the Property Law that I have is from July 2005; the text of the letter indicates that Gong is basing his comments on reports of the draft published on Oct. 30, 2006 in the People's Daily. Here are some articles from that date available from the People's Daily's Web site that comment on the most recent draft and give some indication as to its content: here | here | here | here | here | here | here | here | here | here | here | here. You can see more by going to this page, entering the characters 物权法, and adding an appropriate date restriction.

Gong also has a long article denouncing the Property Law here. Both his article and the open letter are posted on the Mao Flag site, which is dedicated to the restoration of Mao Zedong Thought to Chinese politics. (One commenter to Gong's piece thinks it's about time for another Cultural Revolution.)